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HIV AIDS

What is HIV/AIDS?

The term AIDS (Acquired Immune Deficiency Syndrome) refers to the most advanced stages of an infection caused by the human immunodeficiency virus (HIV). The current definition of AIDS includes:

  • All HIV-infected people who have fewer than 200 CD4+ T cells (also called T4 cells). These cells are key infection fighters in the body’s immune system. Healthy adults often have CD4+ T-cell counts of around 600 or more.

  • HIV-infected people who have been diagnosed with 1 or more health conditions that affect people with advanced HIV disease. These conditions include certain cancers. They also include infections that occur because of HIV’s effect on the immune system (called opportunistic infections).

According to the CDC, about 1.5 million adults and teens are living with HIV infection in the U.S. Many more people are living with HIV infection outside the U.S., particularly in sub-Saharan Africa. The HIV epidemic is still not well-controlled in some parts of the world.

What causes HIV/AIDS?

AIDS is caused by the human immunodeficiency virus (HIV). HIV destroys or hurts immune system cells. It weakens the body's ability to fight infections and certain cancers. HIV is most often spread by having sex with an infected partner whose HIV is not diagnosed or not under control. Another way to spread HIV is by having contact with infected blood from contaminated needles, syringes, or other drug equipment.

HIV can’t be cured. But it can be controlled. And much of the damage from the infection can be reversed or prevented. But if HIV is left untreated, serious infections and cancers occur because of the weakened immune system. And the virus can be passed on to others.

Who is at risk for HIV/AIDS?

The risk of becoming infected with HIV depends on the type of activity. HIV is spread through blood, pre-seminal fluid and semen, fluids from the vagina and rectum, and breastmilk. So these types of behaviors put people at risk of getting or becoming infected with HIV:

  • Having vaginal or anal sex with a person infected with HIV whose virus is not under control. Sexual contact is the most common way the virus is spread. The virus enters the body through the lining of the vagina, penis, rectum, or mouth during sexual activity. Unprotected anal sex has the highest risk of transmission.

  • Having multiple sex partners. This includes any partners whose HIV status is not known. It also includes a partner who has HIV, but whose virus is not under control. Or a partner who has poor or uncertain control of their HIV.

  • Having high-risk sexual partners. This includes a partner who is a sex worker, or someone who has sex with many other people. Or someone who uses IV drugs.

  • Sharing needles, syringes, or other drug equipment with someone with HIV whose virus is not under control.

Other factors that can put people at risk include:

  • Using alcohol and other drugs. These can harm someone’s judgment. They make it more likely that people will do risky things such as having unprotected sex.

  • Having a sexually transmitted disease (STD). STDs can cause changes in the tissue of the vagina or penis. They can make it easier for HIV to pass while you’re having sex

  • Having an accidental stick from a needle or medical device contaminated with HIV. But it is rare for a person with HIV to spread the virus to a healthcare worker this way. Or for a healthcare worker to spread the virus to a patient.

  • Having a blood transfusion. HIV may also be spread through contact with infected blood. But the risk of getting HIV from blood transfusions is very low. This is because blood is screened for signs of HIV infection in the U.S.

  • Having sex without knowing your partner’s HIV status.

Risks to an unborn child. A mother infected with HIV can give her baby the virus before or during birth. This is especially true if her HIV is not well controlled. She can also pass the virus by breastfeeding. Pregnant women should always be tested and treated for HIV.

Being exposed to these things does not put you at risk for getting HIV/AIDS:

  • Saliva

  • Sweat

  • Tears

  • Casual contact, such as sharing food utensils, towels, and bedding

  • Swimming pools

  • Telephones

  • Toilet seats

  • Biting insects (such as mosquitos)

What are the symptoms of HIV/AIDS?

Many people develop a flu-like illness within 2 to 6 weeks after exposure to the HIV virus. But about 5 out of 10 people don’t have any symptoms at all when they first become infected. In addition, the symptoms that do appear often go away within a week to a month. And they are often mistaken for those of another viral infection. These symptoms may include:

  • Fever

  • Headache

  • General feeling of discomfort (malaise)

  • Enlarged lymph nodes

  • Rash

Constant or severe symptoms may not show up for 10 years or more after HIV first enters the body in adults. In children born with an HIV infection, it may take 2 years for symptoms to appear. This period of no symptoms can be different for each person. But during this time, HIV is actively infecting and killing immune system cells. Its most clear effect is a decrease in the number of CD4+ T cells. These cells are key infection fighters in the immune system.

As the immune system weakens, complications or symptoms begin to appear. Symptoms of advanced HIV disease and AIDS may be different for each person. Symptoms may include:

  • Lymph nodes that stay enlarged for more than 3 months

  • Lack of energy

  • Weight loss

  • Frequent fevers and sweats

  • Constant or frequent yeast infections (oral or vaginal)

  • Constant skin rashes or flaky skin

  • Diarrhea that keeps coming back

  • Short-term memory loss

  • One or more infections (opportunistic infections) linked to having a weakened immune system. These include tuberculosis and certain types of pneumonia.

Some people develop frequent and severe herpes infections. These cause mouth, genital, or anal sores, or a painful nerve disease known as shingles. Children may have delayed development or slowed growth (failure to thrive).

During the course of the HIV infection, most people have a slow decline in the number of CD4+ T cells. Some people may have sudden and severe drops in these cell counts.

The symptoms of HIV infection may look like other health conditions. Always talk with your healthcare provider for a diagnosis. Quick diagnostic tests are available and early diagnosis is important.

How is HIV/AIDS diagnosed?

There are several types of HIV tests used to diagnose HIV infection. Early HIV infection often causes no symptoms. It must be found by testing a person's blood for disease-fighting proteins (antibodies) against HIV. Or the virus itself can be detected. Tests used to find antigen-antibody are a preferred method of testing. Antigens are foreign substances (virus). They cause a response from the body’s immune system. Antibodies are made by the body to fight the antigens. Testing for antibodies and the virus may not be positive until 2 to 12 weeks after infection. People exposed to HIV should be tested for HIV infection as soon as they think they may have been exposed to the virus. In some cases a person may have been recently exposed or possibly exposed to HIV and early testing is negative. Then repeat testing in 2 to 12 weeks will often be advised. 

How is HIV/AIDS treated?

As with many other conditions, finding HIV early offers more chances for successful treatment. Antiviral medicines for HIV can stop the virus from further harming the body. This allows some or all of the damage to be healed. People can then often live a normal life span and have a normal sex life and family life.

There is currently no cure for HIV infection. But people who takes the medicines and stay on them may be able to keep the virus completely under control. Talk with your healthcare provider for more information regarding various medicine therapies for the treatment of HIV/AIDS.

A lot of research is being done to find a vaccine that might either prevent HIV infection or help the body to better control HIV infection. Currently, no vaccine has been shown to be effective enough to be used.

Key points about HIV/AIDS

  • AIDS is caused by the human immunodeficiency virus (HIV). HIV destroys or hurts immune system cells. It weakens the body's ability to fight infections and certain cancers.

  • HIV is most often spread by having sex with an infected partner. It can also spread by having contact with infected blood from contaminated needles, syringes, or other drug equipment.

  • A mother infected with HIV can give her baby the virus before or during birth. She can also pass the virus by breastfeeding.

  • Many people have a flu-like illness within 2 to 6 weeks after exposure to the HIV virus. But about 5 out of 10 people don’t have any symptoms at all at first.

  • HIV can’t be cured. But it can be controlled with antiviral medicines.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.

  • Before your visit, write down questions you want answered.

  • Bring someone with you to help you ask questions and remember what your provider tells you.

  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

  • Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

  • Ask if your condition can be treated in other ways.

  • Know why a test or procedure is recommended and what the results could mean.

  • Know what to expect if you do not take the medicine or have the test or procedure.

  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.

  • Know how you can contact your provider if you have questions.

Online Medical Reviewer: Barry Zingman MD
Online Medical Reviewer: Lu Cunningham
Date Last Reviewed: 2/1/2019
© 2000-2019 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.